Diverse hypotheses have been proposed with the aim to explain the extinction of Late Pleistocene/Holocene mammals, including the Megafauna from America. Some authors support that human being was the direct responsible of extinction by means of intensive hunting, as proposed by the “blitzkrieg” or overkilling hypothesis. However, evidence is not conclusive. As is well known by biologists, exotic diseases may play an important role in local extinction of diverse vertebrates. On this basis, some speculated that the arrival of man may also have introduced new diseases that may have played an important role on native mammals, especially megafaunal populations, probably constituting a key factor on their extinction. Recent findings of the parasite Fasciola hepatica in endemic deer from Holocene sites in Patagonia (and also probably from camelids in Peru) previous to Hispanic colonization constitute indirect evidence that may sustain this hypothesis. Because one of the main definite host of this parasite are humans, this potential disease may have been introduced by human populations as hosts and then disperse through the entire continent, as evidenced by the finding of Fasciola hepatica in Patagonia. Its presence in endemic deer and camelids previous to Hispanic colonization, reinforces the proposal that human-related diseases may have played some role in Late Pleistocene extinction of large native mammals.

为了解释晚更新世/全新世哺乳动物（包括来自美国的大型动物）的灭绝，提出了各种假设。一些作者支持，如“闪电战”或过度杀伤性假说所提出的那样，人类是通过强烈狩猎而灭绝的直接原因。但是，证据尚无定论。正如生物学家所熟知的，外来疾病可能在各种脊椎动物的局部灭绝中发挥重要作用。在此基础上，有人推测，人类的到来也可能带来了新的疾病，这些疾病可能对本地哺乳动物，特别是巨型动物种群起了重要作用，可能构成了其灭绝的关键因素。寄生虫Fasciola hepatica的最新发现西班牙裔殖民之前来自巴塔哥尼亚全新世遗址（也可能来自秘鲁骆驼科）的地方性鹿种构成了可能支持这一假说的间接证据。因为这种寄生虫的主要确定宿主之一是人类，所以这种潜在的疾病可能是人类作为宿主引入的，然后传播到整个大陆，这在巴塔哥尼亚发现了肝片状Fasciola。它在西班牙殖民之前就存在于地方性鹿和骆驼科动物中，这进一步证明了与人类有关的疾病可能在大型原生哺乳动物晚更新世灭绝中发挥了一定作用。